With every run he makes, the decision becomes more difficult, the question more pressing.

Is Michael Bennett a luxury the Chargers can afford?

“I like Michael Bennett,” head coach Norv Turner said after Saturday's game at Atlanta. “He's having a good training camp. He's shown he's got juice to make big plays. He's still got that burst.”

Bennett on Saturday took a screen pass and ran 48 yards for a touchdown among his 106 total yards from scrimmage. He has a touchdown in all three preseason games and 59 yards on 18 carries. He has been good at picking up blitzes, he can catch, and he clearly still has more than a trace of the speed that made him the Minnesota Vikings' first-round pick in 2001.

“I've been given an opportunity to play and showcase what I can do,” he said. “I'm definitely happy with it.”

But it might not be enough to stay in San Diego, which Bennett earnestly says is his preference.

On a roster deep with backs and precious little space at the bottom, the Chargers' decision before the Sept. 5 final roster cuts will come down to keeping Bennett or fullback Mike Tolbert.

And that judgment will come down to how they feel best protected in the event of a catastrophe — an injury that would keep LaDainian Tomlinson out of a game or games.

With the Chargers not believing Darren Sproles is an every-down back, a scenario without Tomlinson would require them to look beyond their No. 2 tailback.

They will keep fourth-round pick Gartrell Johnson, because they like his potential. But they almost certainly won't want to hand him the ball 20 times or more in a game this season.

So Bennett's fate in San Diego comes down to whether the team's emergency plan at tailback is him or fullback Jacob Hester.

Hester was drafted in 2008 as a fullback/running back hybrid. He spent most of last season working at running back, but he's the starting fullback this year.

If they decide Hester is the fallback option, Tolbert will make the roster. In fact, Tolbert's ability on special teams is what makes this the likely outcome.

But Bennett is forcing them to think.

At 31 years old and about to begin his ninth season in the NFL, he has found a fountain of youth, a flash not apparent in the past three seasons spent bouncing from Kansas City to Tampa Bay before being claimed off waivers by the Chargers last November.

He says his legs are fresh (just 158 touches since 2006) and that reuniting with Chargers strength and conditioning coach Jeff Hurd was a blessing.

“I had him in Kansas City,” Bennett said. “(Hurd is) a guy you're talking about that prepares players to be at their max — the speed training and lifting. Reconnecting with him really helped me.”

The Chargers would be able to go with just Hester at fullback because they have tight ends Brandon Manumaleuna and Kris Wilson ready to work at fullback, if necessary.

But this is a quandary because Tolbert has had a fantastic preseason on special teams. The team's decision makers say he deserves to be on this roster as much as Bennett, and if all goes according to plan (as in, LT remains healthy) Tolbert would likely be able to help the Chargers more than Bennett.

And that's fine with Tolbert, the Chargers' starting fullback most of '08.

“I love special teams,” Tolbert said. “I love to run and hit. What other place can you do that? I'm not doing it on offense. If you can play they'll find a place to put you. I've just been working, and God willing they'll find a place for me on the roster.”

Bennett, for his part, knows he has proved he can still play and will land somewhere if he gets cut here. But he's grown fond of his teammates and believes the Chargers are on the precipice of something special.

“It's a great feeling (to be doing well), but at the end of everything I want to be here,” he said. “I want to be a part of this team. I think we have a chance to win a Super Bowl. It will be a magical season, and I want to be part of it.”